INTRODUCTION

Before World War II almost all arable tracts of land in Greece featured some trees, either planted or indigenous, the latter being remnants of the ancient forests that had been cleared for cultivation. These trees were preserved in order to guarantee the provision of firewood and fruit for the farmer’s household needs, shade for relaxing during lunch in the hot summer days, fruit and foliage for animal feed, and crop protection from adverse weather conditions. The intercropping of trees with agriculture yielded multiple products and services. Although it was more laborious and provided a relatively low income, it required limited energy use, therefore constituting a sustainable production system for arable agriculture..

systems

Environmental Problems Of Arable Land

Post-war labour mechanization, as well as the use of chemical fertilizers and pesticides, resulted in the intensification of agricultural activities, transforming traditional polycultural systems into monocultures. The main victims of this intensification were trees, which were uprooted because they obstructed agricultural machinery but also in order to increase the “productive” area of farms, a practice also dictated by the Common Agricultural Policy (CAP) of the ‘80s and early ‘90s. Consequently, several arable farms were deprived of their trees, leading to serious environmental problems, especially in the large plains, most of which having been rendered treeless (Figure 1).

Some of the most serious environmental problems that arable land tracts currently face are: soil erosion by water and wind, mainly in the hilly and steep tracts cultivated with annual crops, especially where inappropriate cultural methods (e.g. ploughing down slope/ vertically to the contour lines) are also applied, salinization caused by irrigation with brackish water resulting in the accumulation of salts in the soil, nitrate pollution due to the excessive use of fertilizers, particularly nitrogenous ones, leading to the accumulation of large quantities of nitrogen oxides in the water, soil and plants, and loss of biodiversity due to monoculture and the use of pesticides.

All these problems led to a significant reduction in productivity, desertification and farm abandonment. For example, 120 thousand hectares of annual crops were abandoned in Thessaly from 2000 to 2018 due to the continuous soil degradation and reduction of crop yields below profitable levels (Danalatos et al. 2022).